Fetal Bovine Serum in Vaccines

Instead, the FDA explains why fetal bovine serum might be in some vaccines:

“In the manufacture of viral vaccines, the virus may be grown in cells. These cells need a source of nutrition, which in some instances may be provided by fetal bovine serum.”

Common Ingredients in U.S. Licensed Vaccines

So fetal bovine serum is used as a growth media to provide nutrients to viruses.

What about bovine serum albumin?

Bovine serum albumin actually comes from fetal bovine serum. It is one of the major components and is very similar to human serum albumin.

“Bovine serum albumin (BSA) is a major component of fetal bovine serum (FBS), which is commonly used as a culture medium during vaccine production. Because BSA can cause allergic reactions in humans the World Health Organization (WHO) has set a guidance of 50 ng or less residual BSA per vaccine dose.”